1. Field of Invention
The present invention relates to a white balance adjustment method and a digital image capturing device using the same, and more particularly, to a white balance adjustment method that utilizes the brightness difference.
2. Description of the Related Art
Generally speaking, the colors that reflect off an object will depend on the color of the light sources. The human brain is able to detect and correct this type of color change. Whether it is a sunny day, a cloudy day, in a room with light bulbs or fluorescent lamps, the human eye can adapt to the changes in color under different light sources and it will not affect the way in which humans perceive white objects. However, the “white color” generated by different light sources is perceived differently by a digital image capturing device. For example, a photo tends to be yellowish if it is taken in a room illuminated with tungsten lamps (light bulbs), and it tends to be lightly bluish or reddish if it is taken in other environments.
In order to make the colors in the photos be consistent with the colors perceived by the human eye, the digital image capturing device has to mimic the human brain and adjust the colors according to the light source. It has to define the white color so that in the photos it is the same as the white color perceived by the human eyes. This type of adjustment is known as “white balance”.
Even though at present, the digital image capturing devices may automatically perform white balance adjustments in view of the located environment, it usually define the gray color by obtaining the red (R), green (G) and blue (B) values and does not take the effect of a flash into consideration. Actually, the brightness of the flash will affect the white balance such that the digital image capturing device will not be able to display the image colors at its best.
Therefore, by providing a white balance adjustment method that takes into consideration the effect of the flash on the white balance, the digital image capturing device using the white balance adjustment method of the present invention will be able to display color images with better image qualities.